Ricoh B286 Service Manual page 227

546 A Fusing Temperature Errors
The machine detected that the fusing
temperature was fluctuating out of
range for more than 60 sec. (7
readings detected temperature
fluctuating more than ±20
547 D Zero-Cross Signal Errors
This error occurs if the machine fails
to detect 50/60 Hz on the power
supply line.
Note: The zero-cross signal from the
ac power supply generates a trigger
pulse to control the power supply of
power. (It automatically detects 50/60
Hz.)
551 A Pressure roller center thermistor error 1
During the hot roller temperature
control sequence, or while the hot
roller and pressure roller were
rotating, the pressure roller center
thermistor measured a value
higher than 3.3V 10 consecutive
times at 600 ms intervals.
SM
! Thermistor connection loose,
disconnected, defective
! Hot roller thermistor not positioned
correctly
! Fusing lamp connections loose,
o
C) disconnected, defective
! MCU defective
! Check that the frequency of the
power supply to the machine is
correct
! PSU defective
! MCU defective
! Pressure roller center thermistor not
positioned properly
Pressure roller center thermistor
!
connector loose, broken, defective
! Pressure roller center thermistor
defective
! MCU defective
4-9
SC Code Descriptions
B286/B289